Process and apparatus for the production of mineral and slag wool



P. SMOUT MINERAL AND SLAG WOOL Filed Oct. 15, 1952 Inventor":

SP1 0W WILLE CoRIYELlS PE-rRus BY: haw/f ml PROCESS AND APPARATUS FOR THE PRODUCTION OF Oct. 22, 1957 PROCESS AND APPARATUS FOR THE PRODUC- TION F MINERAL AND *SLAG WOOL Willem Cornelis Petrus Smont, Wittlaer, Bezirk Dusseldorf, Germany Application October 15, 1952, Serial No. 314,767

Claims priority, application Germany January 14, 1952 12 Claims. (Cl. 182.5)

The value of mineral wool or slag wool is decisively determined by the filament length and the bead or granule content. In the most economical and important process of production, which consists in blowing the fused mass with the aid of compressed gases, the filament length is limitedin contrast 'to the costly drawing processes and'a certain bead content must be accepted.

Every eifort is therefore made to conduct the blowing process so that the filaments are as long as possible and the bead content is as low as possible. This problem has not yet been solved, especially when using the liquid slag from the blast furnace since there is no possibility of improvement by means of the chemical composition.

The present invention is based upon the general principle of carrying away the poured stream of slag gradually over a longer distance than heretofore instead of atomising it all at once as is usual in known processes. For this purpose, the atomising medium, for example air or steam, is caused to act on the vertically descending stream of slag substantially at right angles to the direction of flow thereof and .over a length thereof which is greater than twice its thickness. The length of the zone of action preferably amounts to 8-12 times the thickness of the stream of slag.

In a preferred process according to the invention the atomising medium is directed in the form of two wide "fiat bands on to the two sides of the stream of slag so that the said stream is gradually carried away from the sides and is drawn out into the form of wool. The atomising medium is thus directed substantially tangentially on to the stream of slag.

An apparatus for carrying out the process according to the invention, comprises a nozzle or jet having two parallel-spaced slots for the delivery of the atomising medium, the length of the slots being at least ten times as great as the width.

In a preferred construction of apparatus an aperture is provided between the slots for the passage of air, arranged so that no eddying occurs between the two bands of atomising medium which act on the stream of slag and no undesirable influence is exerted on the latter, so that it is actually laterally acted on by the atomising medium and thereby carried away in accordance with the general principle of the invention.

Further a number of apparatus may be arranged in juxtaposition to one another thus blowing a number of streams issuing parallel to one another. In this case, jets of smaller thickness can be employed than when a single thick jet is fed to the atomising arrangement.

An apparatus according to the invention is diagrammatically illustrated in the figure and the process according to the invention will be described with reference thereto.

The atomising medium, for example compressed gas, compressed .air :and compressed steam, passes through the tube 1 into two arms of the forked or U-shaped blowing nozzle 2. Slots 3 parallel .or substantially parallel to a I atent 0 one another are formed one in each arm of the blowing nozzle. The width of the slots is constant or substantially constant over their entire length which is at least ten times as great as the slot width. While in the drawing the two arms are rigidly connected together and the distance between the slots is therefore fixed, the two parts of blowing nozzle in which the slots are formed may be arranged separately from one another'and adapted to be adjusted in relation to one another. It is then possible to adjust the distance between the slots and to adapt it to the thickness of the stream 5 of the nozzle.

In addition, the nozzle arms containing the slots may be arranged to rotate about a longitudinal axis in order that the direction of the issuing band of atomising medium may thus be influenced. I

In the arrangement shown in the drawing, the bands of atomising medium leave the slots 3 parallel to one another and perpendicularly to the plane of'the atomising nozzle 2.

A recess 4 is formed between the arms of the atomising nozzle and between the slots 3. The said recess serves to direct the atomising medium in the form of flat wide bands on to the sides of the stream of slag without eddying. The atomising medium then carries the molten mass away from these sides and draws it out in the form of wool comprising very long fibres and few beads or granules, because the filaments adhere to the liquid slag streams 5 atone end and can thus be drawn out to a slag travelling past great length. The pressure of the atomising medium is adapted to the particular conditions by a regulating device and amounts, for example, to 5 atmospheres above atmospheric pressure.

Nozzle members 2 and 2' may be adjusted at a desired spacing'from each other bymeans of slots 8 in connecting member 6, in combination with screws 7. Liquid slag stream 5 is shown to flow from trough 9 through bottom opening 10 thereof. Trough 9 with bottom opening 10 comprise means for producing a flow of fiber-forming material in a predetermined path. Y

The process and the apparatus have been found particularly successful in the production of slag wool from the blast furnace, that is to say, from slag worked up in the heat emanating from the blast furnace. The slag flows down from an aperture situated in the bottom of a channel, for example the blast furnace channel, and past the slotted nozzle 2 hereinbefore described, at an appropriate distance therefrom. In a practical constructional example, the thickness of the poured stream of normal blast furnace slag amounted to 10 mm. and compressed air at a pressure of 5 atmospheres above atmospheric pressure was employed as the atomising medium. The width of each slot 3 in the apparatus amounted to 2 mm. and the length thereof to mm., that is, about 10 times the thickness of the stream of slag. Filament lengths of up to 100 cm. were obtained with a bead or granule content of only 3%.

As hereinbefore stated, more than one poured stream of slag may be employed.

It is not essential for the stream of slag to have been completely consumed at the end of the zone of action of the atomising medium. The conditions may be so chosen that only part of the stream of slag is blown into the form of wool, while another part may flow away at the bottom and be taken up, for example, in a ladle.

I .claim:

1. A method of making fibrous material, comprising the steps of producing a flowing stream of fiber forming material in liquid form along a predetermined straight path; and sweeping two separate, spaced streams of gaseous medium respectively across opposite outer portions of said flowing material respectively along substantially parallel planes tangential to said flowing material, so that said portions of said flowing material are drawn out in the form of a fiber by said streams of gaseous medium during passage of said stream of fiber forming material between and in contact with said gas stream.

2. A method of making mineral wool, comprising the steps of producing a flowing stream of slag in liquid form along a predetermined straight path; and sweeping two sep arate, spaced streams of gaseous medium respectively across opposite outer portions of said slag respectively along substantially parallel planes tangential to said fiowing slag, each stream of gaseous medium being elongated along said path of flow of said slag and being of a length greater than twice the thickness of the flowing slag, so that said portions of said flowing slag are drawn out in the form of a fiber by said streams of gaseous medium during passage of said stream of fiber forming material between and in contact with said gas stream.

3. A method of making mineral wool, comprising the steps of producing a flowing stream of slag in liquid form along a predetermined straightpath; and sweeping two separate spaced streams of gaseous medium respectively across opposite outer portions of said slag respectively along substantially parallel planes tangential to said flowing slag and substantially normal to said path of flow thereof, each stream of gaseous ,medinm being elongated along said path of flow of said slag and being of a length approximately 812 times the thickness of the flowing slag, so that said portions of said flowing slag are drawn out in the form of a fiber by said streams of gaseous medium during passage of said stream of fiber forming material between and in contact with said gas stream.

4. Apparatus for producing fibers from fiber forming material, comprising, in combination, means for producing a flow of the fiber forming material along a predetermined straight path; conduit means for supplying a flow of gaseous medium; and a pair of spaced nozzle means connected to said conduit means and respectively formed with elongated openings extending substantially parallel to said path respectively on opposite sides of a plane passing between said openings and including said path for projecting substantially parallel walls of gaseous me dium across said path respectively an opposite sides there of.

5. Apparatus for producing fibers from fiber forming material, comprising, in combination, means for producing a flow of the fiber forming material in along a predetermined straight path; conduit means for supplying a flow of gaseous medium; and a pair of spaced nozzle means connected to said conduit means and respectively formed with elongated openings extending substantially parallelto said path respectively on opposite sides of a plane passing between said openings and including said path for projecting substantially parallel walls of gaseous medium across said path respectively an opposite sides thereof, the length of said openings being at least ten times their width.

6. Apparatus for producing fibers from fiber forming material, comprising, in combination, means for producing a flow of the fiber forming material along a predetermined straight path; conduit means for supplying a flow of gaseous medium; a pair of spaced nozzle means cnnected to said conduit means and respectively formed with elongated openings extending substantially parallel to said path respectively on opposite sides of a plane passing between said openings and including said path for projecting substantially parallel walls of gaseous medium across said path respectively an opposite. sides thereof and adjustable connecting means connecting said nozzle means together for adjustably spacing the same relative to each other to adjust the positions of said elongated openings relative to each other.

7. A method of making fibrous material, comprising the steps of producing a flowing stream of fiber forming material in liquid form along a predetermined straight path; and sweeping two separate, spaced streams of gase ous medium respectively across opposite outer portions of said flowing material respectively along substantially parallel planes tangential to said flowing material, each stream of gaseous medium being elongated along said path of flow of said material, so that said portions of said flowing material are drawn out in the form of a fiber by said stream of gaseous medium during passage of said stream of fiber. forming material between and in contact with said gaseous stream.

8. A method of making fibrous material, comprising the steps of producing a flowing stream of fiber forming material in liquid form falling along a predetermined straight path; and sweeping twoseparate, spaced streams of gaseous medium respectively across opposite outer portions of said flowing material respectively along sub stantially parallel planes tangential to said flowing material substantially normal to said path of flow thereof, each stream of gaseous medium being elongated along said path of flow of said material, so that said portions of said flowing material are drawn out in the form of a. fiber by said stream of gaseous medium during passage of said stream of fiber forming material between and in contact with said gaseous stream.

9. A method of making fibrous material, comprising the steps of producing a flowing stream of fiber forming material in liquid form along a predetermined straight path; sweeping two separate, spaced streams of gaseous medium, respectively across opposite outer portions of said flowing material respectively along substantially parallel planes tangential to said flowing material, each stream of gaseous medium being elongated along said path of flow of said material; and maintaining a free air passage between said streams of gaseous medium in the direction of flow thereof, so that said portions of said flowing material are drawn out in the form of a fiber by said stream of gaseous medium during passage of said stream of fiber forming material between and in contact with said gaseous stream.

10. A method of making mineral wool, comprising the steps of producing a flowing stream of slag in liquid form along a predetermined straight path; sweeping two separate, spaced streams of gaseous medium respectively across opposite outer portions of said slag respectively along substantially parallel planes tangential to said flowing slag and substantially normal to said path of flow thereof, each stream of gaseous medium being elongated along said path of flow of said slag and being of a length approximately 8-12 times the thickness of the flowing slag; and maintaining a free air passage between said streams of gaseous medium in the direction of flow thereof, so that said portions of said flowing slag are drawn out in the form of a fiber by said streams of gaseous medium during passage of said stream of fiber. forming material between and in contact with said gas stream.

11. Apparatus for producing fibers from a stream of fiber forming material flowing along a predetermined straight path, comprising, in combination, means for providing along said path a stream of predetermined width of fiber forming material; conduit means for supplying a flow of gaseous medium; and a pair of spaced nozzle means connected to said conduit means and respectively formed with elongated openings extending substantially parallel to each other and to said path respectively on opposite sides of a plane passing between said openings and including said path, said elongated openings, respectively, having inner edges spaced from each other at a distance substantially equal to said predetermined width, for projecting substantially parallel walls of gaseous medium across said path respectively on opposite sides thereof. i

12. Apparatus for producing fibers from a stream of fiber forming material flowing along a predetermined straight path, comprising, in combination, means for pro viding along said path a stream of predetermined width of fiber forming material; conduit means for supplying a flow of gaseous medium; a pair of spaced nozzle means connected to said conduit means and respectively formed with elongated openings extending substantially parallel to each other and to said path respectively on opposite 5 sides of a plane passing between said openings and including said path, said elongated openings, respectively, having inner edges spaced from each other at a distance substantially equal to said predetermined width, for projecting substantially parallel walls of gaseous medium across said path respectively on opposite sides thereof; and means for maintaining a free air passage between said walls of gaseous medium in the direction of flow thereof.

References Cited in the file of this patent UNITED STATES PATENTS 

